SPOJ: BGSHOOT ( SegmentTree-DS)

SPOJ: BGSHOOT ( Segment Tree-DS )
///==================================================///
///                HELLO WORLD !!                    ///
///                  IT'S ME                         ///
///               BISHAL GAUTAM                      ///
///         [ bsal.gautam16@gmail.com ]              ///
///==================================================///
#include<bits/stdc++.h>
#define X first
#define Y second
#define mpp make_pair
#define nl printf("\n")
#define SZ(x) (int)(x.size())
#define pb(x) push_back(x)
#define pii pair<int,int>
#define pll pair<ll,ll>
///---------------------
#define S(a) scanf("%d",&a)
#define P(a) printf("%d",a)
#define SL(a) scanf("%lld",&a)
#define S2(a,b) scanf("%d%d",&a,&b)
#define SL2(a,b) scanf("%lld%lld",&a,&b)
///------------------------------------
#define all(v) v.begin(),v.end()
#define CLR(a) memset(a,0,sizeof(a))
#define SET(a) memset(a,-1,sizeof(a))
#define fr(i,a,n) for(int i=a;i<=n;i++)
#define UNIK(v) sort(all(v)),v.resize( unique(all(v)) -v.begin() );
using namespace std;
typedef long long ll;
///==========CONSTANTS=============///
///  Digit     0123456789012345678 ///
#define MX     200005
#define inf    1000000010
#define MD     1000000000LL
#define eps    1e-9
///===============================///

int xx[MX+2],qx[MX+2],yy[MX+2],qy[MX+2];
int lim,ar[2*MX+2],dp[2*MX+2][22];

void Rmq( ) {
    for(int i=1; i<=lim; i++)dp[i][0]=ar[i];
    for(int j=1; (1<<j)<=lim; j++) {
        for(int i=1; i+(1<<j)-1<=lim; i++) {
            dp[i][j]=(dp[i][j-1]>dp[i+(1<<(j-1))][j-1])?dp[i][j-1]:dp[i+(1<<(j-1))][j-1];
        }
    }
}

int Qry(int l,int r) {
    int k=log2(r-l+1);
    return (dp[l][k]>dp[r-(1<<k)+1][k])?dp[l][k]:dp[r-(1<<k)+1][k];
}

vector<int>v;
int main() {
    int tc,cs=1,i,j,k,n,m,q,x,y;
    S(n);
    fr(i,1,n) {
        S2(xx[i],yy[i]);
        v.pb( xx[i] );
        v.pb( yy[i] );
    }
    S(m);
    fr(i,1,m) {
        S2(qx[i],qy[i]);
        v.pb( qx[i] );
        v.pb( qy[i] );
    }
    UNIK(v);
    lim=0;
    fr(i,1,n) {
        x=lower_bound( all(v),xx[i] )-v.begin()+1;
        y=lower_bound( all(v),yy[i] )-v.begin()+1;
        ar[x]++;
        ar[y+1]--;
        lim=max(lim,y+2);
    }
    fr(i,1,lim) {
        ar[i]+=ar[i-1];
    }
    Rmq( );
    ll sm=0LL;
    fr(i,1,m) {
        x=lower_bound( all(v),qx[i] )-v.begin()+1;
        y=lower_bound( all(v),qy[i] )-v.begin()+1;
        int mx=Qry(x,y);
        printf("%d\n",mx);
    }
    return 0;
}